Inter-device coordination method and device

Abstract

In an embodiment of the present invention, there is provided a method and an apparatus for inter-device coordination, the method including: a first terminal device receiving first sidelink information from a second terminal device and second sidelink information from a third terminal device; determining based on the first sidelink information and the second sidelink information that a first resource reserved by the first sidelink information needs to be reselected; and sending first coordination information to the second terminal device for indicating that the first resource needs to be reselected, where a priority of the first coordination information is equal to a highest priority of the first sidelink information and the second sidelink information.

Description

[Technical Field]

[0001] The present invention relates to the field of communications. [Background technology]

[0002] V2X (Vehicle to Everything) is a vehicle communication technology. Compared to cellular communication using a Uu link, V2X transmitters communicate directly with receivers via a sidelink. NR New Radio V2X is a key project of 5G Rel-16. Compared to Rel-14 / Rel-15 LTE (Long Term Evolution) V2X, NR V2X supports more scenarios and services and can meet higher performance needs.

[0003] The physical channels defined in Rel-16 NR V2X include the Physical Sidelink Control Channel (PSCCH), the Physical Sidelink Shared Channel (PSSCH), and the Physical Sidelink Feedback Channel (PSFCH). The PSCCH carries the first-stage sidelink control information (SCI), and the first-stage SCI is mainly used for resource reservation. The PSSCH carries the second-stage SCI and transport block (TB), of which the second-stage SCI is mainly used for TB demodulation.

[0004] The PSFCH carries sidelink feedback information (also known as HARQ-ACK). The PSCCH and PSSCH are usually transmitted in the same slot. One PSCCH / PSSCH is associated with one or more PSFCH resources according to a predetermined rule, and after transmitting the PSCCH / PSSCH, a device can receive an acknowledgement (ACK) / negative acknowledgement (NACK) on the associated PSFCH resource. NR V2X supports HARQ-ACK feedback for unicast and groupcast. Groupcast also includes two HARQ-ACK feedback modes: HARQ Option 1 and HARQ Option 2.

[0005] For groupcast in HARQ option 1, only receiving devices within a predetermined communication range can feed back HARQ-ACK, and only NACKs (NACK-only) are fed back. Specifically, all receiving devices share the same PSFCH resource, i.e., all use the same PSFCH resource for feedback, and only provide feedback (transmit PSFCH) when there is a NACK, and do not transmit PSFCH when there is an ACK. ACK and NACK are distinguished by the presence or absence of a PSFCH signal, and PSFCHs transmitted by multiple devices may be superposed in the same direction on the same resource. The transmitting device determines whether it is a NACK or an ACK based on the presence or absence of a PSFCH signal. However, the transmitting device does not know which receiving device specifically sent the NACK.

[0006] For HARQ option 2 groupcast, the PSFCH resource of each receiving device for feeding back ACK / NACK is independent, the receiving device feeds back ACK when it receives correctly and feeds back NACK when it does not receive correctly, ACK and NACK are distinguished by different PSFCH sequences (cyclic shift), and the transmitting device knows which receiving device sends the ACK / NACK.

[0007] The resources (time-frequency resources) used for sidelink transmission are in a resource pool. NR V2X defines two working modes. For NR V2X Mode 1, the resources of the terminal device used for V2X communication are scheduled or configured by the network device (base station) via the NR Uu link. For NR V2X Mode 2, the terminal device can autonomously select time-frequency resources for V2X communication based on the sensing result.

[0008] It should be noted that the introduction of the above background art is intended to clearly and completely explain the technical solutions of the present invention and to facilitate understanding by those skilled in the art, and these technical solutions described in the background art of the present invention should not be construed as being known to those skilled in the art. Summary of the Invention [Problem to be solved by the invention]

[0009] The inventors discovered the following: In Rel-16 NR V2X resource autonomous selection (Mode 2), the terminal device selects and transmits resources based on its own sensing results, which can avoid interference or collisions between devices to some extent. However, resource transmission collisions can still occur in some cases. Therefore, as an enhancement to resource autonomous selection Mode 2, inter-UE coordination is also one of the research topics for Rel-17 V2X. Specific methods for inter-UE coordination are still being studied and are awaiting resolution.

[0010] In view of at least one of the above problems, an object of an embodiment of the present invention is to provide a method and apparatus for inter-device coordination. [Means for solving the problem]

[0011] According to one aspect of an embodiment of the present invention, there is provided a method for coordination between devices, the method comprising: a first terminal device receiving first sidelink information from a second terminal device and second sidelink information from a third terminal device; determining, based on the first sidelink information and the second sidelink information, that a first resource reserved by the first sidelink information needs to be reselected; and sending first coordination information to the second terminal device to indicate that the first resource needs to be reselected, wherein a priority of the first coordination information is equal to the highest priority of the first sidelink information and the second sidelink information.

[0012] According to one aspect of an embodiment of the present invention, there is provided an inter-device coordination device, which includes: a receiving unit for receiving first sidelink information from the second terminal device and second sidelink information from the third terminal device; a determining unit for determining, based on the first sidelink information and the second sidelink information, that first resources reserved by the first sidelink information need to be reselected; and a transmitting unit for transmitting first coordination information to the second terminal device to indicate that the first resource needs to be reselected, the priority of the first coordination information being equal to the highest priority of the first sidelink information and the second sidelink information.

[0013] According to another aspect of an embodiment of the present invention, there is provided a method for inter-device coordination, the method comprising: The first terminal device receives sidelink information from the second terminal device; and and transmitting a reselection instruction to the second terminal device to instruct it to perform resource reselection and / or a confirmation or non-confirmation of the sidelink information depending on whether the first terminal device is a destination terminal device of the second terminal device.

[0014] According to another aspect of an embodiment of the present invention, there is provided an inter-device coordination device, the inter-device coordination device comprising: a receiving unit for receiving sidelink information from the second terminal device; and The device further includes a transmitting unit configured to transmit a reselection instruction to the second terminal device to instruct the second terminal device to perform resource reselection and / or a confirmation or non-confirmation of the sidelink information depending on whether the first terminal device is a destination terminal device of the second terminal device.

[0015] According to another aspect of an embodiment of the present invention, there is provided a method for inter-device coordination, the method comprising: The first terminal device receives sidelink information from the second terminal device; and The method includes sending a reselection instruction to the second terminal device to instruct it to perform resource reselection using a first resource or a second resource, depending on whether the first terminal device is a destination terminal device of the second terminal device.

[0016] According to another aspect of an embodiment of the present invention, there is provided an inter-device coordination device, the inter-device coordination device comprising: a receiving unit for receiving sidelink information from the second terminal device; and The device includes a transmitting unit that transmits a reselection instruction to the second terminal device to instruct the second terminal device to perform resource reselection using a first resource or a second resource depending on whether the first terminal device is a destination terminal device of the second terminal device. [Effects of the Invention]

[0017] One of the advantageous effects of the embodiment of the present invention is that the priority of coordination information can be accurately determined, and when determining whether to transmit or drop sidelink information based on a priority rule, the priority of sending a collision indication can be ensured to match the priority of the service, and information related to a high-priority service can be ensured to be transmitted preferentially.

[0018] The following description and reference to the drawings disclose in detail particular embodiments of the present invention, illustrating ways in which the principles of the present invention may be employed, but the scope of the present invention is not limited thereto, and various changes, modifications, and alternatives may be included within the scope of the appended claims.

[0019] Additionally, features described and / or illustrated with respect to one embodiment may be used in the same or similar manner in one or more other embodiments, may be combined with features in the other embodiments, or may be substituted for features in the other embodiments.

[0020] It should be noted that when used in this specification, terms such as "comprise / have" refer to the presence of a feature, element, step, or assembly, but do not exclude the presence or addition of one or more other features, elements, steps, or assemblies. [Brief explanation of the drawings]

[0021] Elements and features described in one drawing or one embodiment of the invention may be combined with elements and features shown in one or more other drawings or embodiments, and in the drawings, like reference numerals are used to indicate corresponding parts in several drawings and to indicate corresponding parts used in multiple embodiments. [Figure 1] 1 is a diagram illustrating a communication system according to an embodiment of the present invention. [Figure 2] FIG. 2 is an exemplary diagram of coordination between devices in an embodiment of the present invention. [Figure 3]FIG. 1 is a diagram illustrating a method for coordination between devices in an embodiment of the present invention. [Figure 4] FIG. 10 is an exemplary diagram of transmitting coordination information in an embodiment of the present invention. [Figure 5] FIG. 1 is a diagram illustrating a method for coordination between devices in an embodiment of the present invention. [Figure 6] FIG. 10 is an exemplary diagram of transmitting coordination information in an embodiment of the present invention. [Figure 7] FIG. 1 is an exemplary diagram of a PSFCH according to an embodiment of the present invention. [Figure 8] FIG. 10 is an exemplary diagram of feedback of a PSFCH in an embodiment of the present invention. [Figure 9] FIG. 10 is another exemplary diagram of feedback of PSFCH in an embodiment of the present invention. [Figure 10] FIG. 1 is a diagram illustrating a method for coordination between devices in an embodiment of the present invention. [Figure 11] FIG. 1 is a diagram illustrating a method for coordination between devices in an embodiment of the present invention. [Figure 12] FIG. 10 is another exemplary diagram of a PSFCH in an embodiment of the present invention. [Figure 13] FIG. 10 is another exemplary diagram of transmitting coordination information in an embodiment of the present invention; [Figure 14] FIG. 10 is another exemplary diagram of transmitting coordination information in an embodiment of the present invention; [Figure 15] FIG. 10 is another exemplary diagram of transmitting coordination information in an embodiment of the present invention; [Figure 16] FIG. 10 is another exemplary diagram of transmitting coordination information in an embodiment of the present invention; [Figure 17] FIG. 10 is another exemplary diagram of transmitting coordination information in an embodiment of the present invention; [Figure 18] FIG. 1 is a diagram illustrating an inter-device coordination device according to an embodiment of the present invention. [Figure 19]FIG. 1 is a diagram illustrating an inter-device coordination device according to an embodiment of the present invention. [Figure 20] FIG. 1 illustrates a network device according to an embodiment of the present invention. [Figure 21] FIG. 2 is a diagram illustrating a terminal device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] The foregoing and other features of the present invention will become more apparent from a consideration of the accompanying drawings and the following description. While the specification and drawings disclose particular embodiments of the present invention, they illustrate only some of the embodiments which may employ the principles of the present invention, and it is to be understood that the present invention is not limited to the described embodiments, but rather includes all modifications, variations, and alternatives which fall within the scope of the appended claims.

[0023] In embodiments of the present invention, the term "communication network" or "wireless communication network" may refer to a network conforming to any communication standard, such as LTE (Long Term Evolution), LTE-A (LTE-Advanced), WCDMA (Wideband Code Division Multiple Access), HSPA (High-Speed ​​Packet Access), etc.

[0024] Additionally, communications between devices in a communications system may be performed according to any level of communications protocol, including, but not limited to, 1G (generation), 2G, 2.5G, 2.75G, 3G, 4G, 4.5G, 5G, New Radio (NR), and / or other conventional or future-developed communications protocols.

[0025] In the embodiments of the present invention, the term "network device" refers to a device that connects a terminal device to a communication network and provides services to the terminal device in a communication system, for example, a network device may include, but is not limited to, a base station (BS), an access point (AP), a transmission reception point (TRP), a broadcast transmitter, a mobile management entity (MME), a network gateway, a server, a radio network controller (RNC), a base station controller (BSC), etc.

[0026] The base station may include, but is not limited to, a Node B (NodeB or NB), an evolved Node B (eNodeB or eNB), a 5G base station (gNB), etc., and may further include a Remote Radio Head (RRH), a Remote Radio Unit (RRU), a relay, or a low-power node (e.g., femto, pico, etc.). The term "base station" may include some or all of the functions thereof, and each base station can provide communication coverage for a specific geographic area. The term "cell" may refer to a base station and / or the area it covers, depending on the context of the term.

[0027] In embodiments of the present invention, the term "User Equipment" (UE) or "Terminal Equipment" (TE) refers to a device that accesses a communication network and receives services from the network, for example, via a network device. A User Equipment may be fixed or mobile, and may also be referred to as a Mobile Station (MS), a terminal, a Subscriber Station (SS), an Access Terminal (AT), a station, etc.

[0028] Among these, user devices may include, but are not limited to, cellular phones, personal digital assistants (PDAs), wireless modems, wireless communication devices, handheld devices, machine-type communication devices, laptop computers, cordless phones, smartphones, smart watches, digital cameras, etc.

[0029] Furthermore, the term "network side" or "network device side" refers to the network side, which may be a base station or a core network device, and may include one or more network devices as described above. The term "user side" or "terminal side" or "terminal device side" refers to the user or terminal side, which may be a UE, and may include one or more terminal devices as described above. In this specification, unless otherwise specified, "device" may refer to either a network device or a terminal device.

[0030] The following describes a scenario in an embodiment of the present invention through an example, but the present invention is not limited thereto.

[0031] Fig. 1 is a diagram showing a communication system in an embodiment of the present invention, taking a terminal device and a network device as an example. As shown in Fig. 1, a communication system 100 may include a network device 101 and terminal devices 102 and 103. For convenience, Fig. 1 illustrates an example in which only two terminal devices and only one network device are used, but the embodiment of the present invention is not limited to this.

[0032] In an embodiment of the present invention, existing or future services may be performed between the network device 101 and the terminal devices 102 and 103. These services may include, but are not limited to, communications related to enhanced Mobile Broadband (eMBB), massive Machine Type Communication (mMTC), and Ultra-Reliable and Low-Latency Communication (URLLC).

[0033] 1 shows that the two terminal devices 102 and 103 are both located within the coverage of the network device 101, but the present invention is not limited to this. Neither of the two terminal devices 102 and 103 may be located within the coverage of the network device 101, or one terminal device 102 may be located within the coverage of the network device 101 and the other terminal device 103 may be located outside the coverage of the network device 101.

[0034] In an embodiment of the present invention, sidelink transmission may be performed between two terminal devices 102 and 103. For example, the two terminal devices 102 and 103 may all perform sidelink transmission within the coverage of the network device 101 to realize V2X communication, or all may perform sidelink transmission outside the coverage of the network device 101 to realize V2X communication, or one terminal device 102 may perform sidelink transmission within the coverage of the network device 101 and the other terminal device 103 may perform sidelink transmission outside the coverage of the network device 101 to realize V2X communication.

[0035] In some embodiments of the present invention, the terminal devices 102 and / or 103 may autonomously select the sidelink resources (i.e., adopt Mode 2), and in such a case, the sidelink transmission is independent of the network device 101, i.e., optional for the network device 101. Of course, in some embodiments of the present invention, the autonomous selection of sidelink resources (i.e., adopt Mode 2) and the allocation of sidelink resources by the network device (i.e., adopt Mode 1) may be combined, but the embodiments of the present invention are not limited thereto.

[0036] In LTE V2X and NR V2X, a terminal device can obtain sidelink transmission resources through the process of sensing, detection, and resource selection, during which the terminal device can obtain the resource occupancy status in the resource pool through continuous sensing. For example, the terminal device can estimate the resource occupancy status in the next period (also called the selection window) based on the resource occupancy status in the previous period (also called the sensing window).

[0037] In Rel-16 NR V2X resource autonomous selection (Mode 2), the terminal device selects and transmits resources based on its own sensing results, thereby avoiding interference or collisions between devices to a certain extent. For the resource selection process, see Section 8.1.4 of the TS38.214 standard (V16.2.0).

[0038] Rel-17 V2X introduces an enhancement to resource autonomous selection mode 2. Device-to-device coordination can improve transmission reliability and reduce transmission latency in mode 2. Device-to-device coordination has already been a research topic in Rel-17 V2X. Device-to-device coordination requires the exchange of information between devices, called coordination information. Coordination information can be used to enhance resource selection in mode 2. Coordination information can indicate whether a conflict exists. Conflicts may include resource collision issues, half-duplex issues, etc.

[0039] In some cases, resource conflict problems may still occur, such as a hidden node problem, where device B transmits sidelink information to device A, and there is an interference source device C around device A, and device B cannot sense device C, so device B's transmission may be interfered with by device C, i.e., device C may be regarded as a hidden node.

[0040] 2 is an example diagram of inter-device coordination in an embodiment of the present invention, in which device C is a hidden node. As shown in FIG. 2, for example, device A can sense device C, so that device A discovers the occurrence of a collision between device B and device C, and then sends a collision indication (e.g., using one bit) to device B and / or device C to instruct device B and / or device C to perform resource reselection, thereby avoiding the hidden node problem described above. This is actually a kind of inter-device coordination.

[0041] In addition, the conventional resource selection in mode 2 may also encounter a half-duplex problem. For example, if device B and device C transmit simultaneously in the same slot, device B and device C cannot receive the sidelink information transmitted by the other device due to the half-duplex limitation, i.e., a half-duplex problem occurs.

[0042] For example, device A can learn of the occurrence of a half-duplex problem between device B and device C by receiving the SCIs transmitted by device B and device C, and can then send a collision indication (for example, using 1 bit) to device B and / or device C to instruct device B and / or device C to reselect resources or retransmit, thereby avoiding the half-duplex problem described above. This is actually a kind of inter-device coordination.

[0043] For now, how device A can indicate to device B whether there is a collision (e.g., due to resource collision and / or half-duplex issues) is still a topic that needs to be researched and resolved. In an embodiment of the present invention, device A can send coordination information to device B, which can instruct device B to perform resource reselection or retransmission.

[0044] For convenience, the coordination information is referred to as indicating a reselection or retransmission. Equivalently, the coordination information may be referred to as indicating the occurrence of a collision (pre-collision or post-collision) or half-duplex problem, and device B may determine to perform resource reselection or retransmission based on the occurrence of a collision (pre-collision), the occurrence of a collision (post-collision), or half-duplex. Equivalently, the coordination information may be referred to as indicating the occurrence of a conflict, and at least a portion of the coordination information may be referred to as a retransmission indication or a reselection indication based on the function of the indication. Equivalently, a reselection indication may be referred to as an indication for an expected conflict.

[0045] In the embodiments of the present invention, the sidelink will be described using V2X as an example, but the present invention is not limited thereto and can be applied to sidelink transmission scenarios other than V2X. In the following description, unless confusion arises, the terms "sidelink" and "V2X" are interchangeable, the terms "PSFCH" and "sidelink feedback channel" are interchangeable, the terms "PSCCH" and "sidelink control channel" or "sidelink control information" are interchangeable, and the terms "PSSCH" and "sidelink data channel" or "sidelink data" are interchangeable.

[0046] Furthermore, transmitting or receiving a PSCCH may be understood as transmitting or receiving sidelink control information carried by the PSCCH, transmitting or receiving a PSSCH may be understood as transmitting or receiving sidelink data carried by the PSSCH, and transmitting or receiving a PSFCH may be understood as transmitting or receiving sidelink feedback information carried by the PSFCH. Sidelink transmission may be understood as transmitting a PSCCH / PSSCH or transmitting sidelink data / information.

[0047] Various embodiments of the present invention will now be described with reference to the accompanying drawings, which are merely illustrative and not limiting of the present invention.

[0048] <Example of the first aspect> In an embodiment of the present invention, an inter-device coordination method is provided, which will be described from the perspective of a first terminal device. A first terminal device (device A) can receive sidelink information (e.g., SCI and PSSCH) transmitted by a second terminal device (device B) and / or a third terminal device (device C).

[0049] 3 is a diagram illustrating a method for device coordination according to an embodiment of the present invention. As shown in FIG. 3, the method includes the following steps (operations):

[0050] 301: The first terminal device receives first sidelink information from the second terminal device and second sidelink information from the third terminal device; 302: The first terminal device determines that it is necessary to reselect a first resource reserved by the first sidelink information based on the first sidelink information and the second sidelink information; and 303: The first terminal device transmits first coordination information for instructing the second terminal device that the first resource needs to be reselected, wherein the priority of the first coordination information is equal to the highest priority among the first sidelink information and the second sidelink information.

[0051] Note that the above Figure 3 is for illustratively explaining an embodiment of the present invention, but the present invention is not limited thereto. For example, the execution order between each operation can be appropriately adjusted, or several operations can be increased or decreased. Those skilled in the art are not limited to the description of the above Figure 3, and can perform appropriate deformations and the like based on the above content.

[0052] In some embodiments, the device may need to transmit coordination information and other information simultaneously. Here, the other information includes sidelink information and / or uplink information, for example, PSFCH, PUSCH, etc., but an exhaustive enumeration is omitted. Due to the limitation of the device capabilities, the device needs to select and transmit M pieces of information from N pieces of information (M < N). The device needs to determine which information to finally transmit based on the priority of the information. The priorities of the sidelink information and the uplink information have already been defined in the standard. How to determine the priority of the coordination information is a problem that needs to be solved.

[0053] In some embodiments, the first SLI includes first SLI control information (SCI) and a first Physical Sidelink Shared Channel (PSSCH), the priority of the first SLI being equal to the priority indicated by a field in the first SLI, and the second SLI includes second SLI and a second Physical Sidelink Shared Channel (PSSCH), the priority of the second SLI being equal to the priority indicated by a field in the second SLI.

[0054] In some embodiments, the first resources reserved by the first sidelink control information and the second resources reserved by the second sidelink control information at least partially overlap in the time and frequency domains.

[0055] 4 is an example diagram of transmission of coordination information in an embodiment of the present invention. As shown in FIG. 4, a certain resource (resource 1) for transmission by device B reserves a next resource (resource 2) by SCI, a certain resource (resource 3) for transmission by device C reserves a next resource (resource 4) by SCI, and resource 2 and resource 4 collide, that is, the time-frequency resources overlap (at least partially overlap in the time domain and the frequency domain, and of course, can overlap completely).

[0056] Device A receives the SCI transmitted by device B on resource 1 and the SCI transmitted by device C on resource 3, and based on these SCIs, it can know that a collision will occur in the future between resource 2 and resource 4 of device B and device C. Therefore, device A transmits coordination information B to device B before the collision occurs, informing device B to perform resource reselection. After receiving coordination information B, device B performs resource reselection, i.e., it can select a resource that does not collide with resource 4 and perform transmission, thereby avoiding the collision.

[0057] Since the coordination information B is used to protect the PSSCHs of device B and device C from collision, the priority of the coordination information B is the same as (equal to) the highest PSSCH priority among device B and device C. Therefore, the priority of the coordination information can be accurately determined, and when determining the transmission or dropping of sidelink information based on the priority rule, the priority of sending a collision indication can be ensured to match the priority of the service, and information related to a high-priority service can be guaranteed to be transmitted preferentially.

[0058] In some embodiments, the first coordination information may be carried by a physical sidelink feedback channel (PSFCH). For example, when the coordination information is used to indicate reselection, the PSFCH resource may be an additional configured or pre-configured RB resource or a sequence resource. Here, the sequence may be determined by a parameter such as a cyclic shift. However, the present invention is not limited thereto, and for example, other resources may also be used to carry the coordination information.

[0059] In some embodiments, the first terminal device is a destination receiving terminal device of the second terminal device. In some embodiments, the first terminal device is not a destination receiving terminal device of the second terminal device, but is a destination receiving terminal device of a third terminal device. The destination receiving terminal device refers to, for example, a receiving device that receives PSCCH / PSSCH. For specific implementation methods, please refer to the embodiments of the sixth aspect described below.

[0060] In some embodiments, the second terminal device performs unicast, groupcast, or broadcast sidelink communication, i.e., the above-described embodiments can be applied to any unicast, groupcast, or broadcast scenario.

[0061] The above-described embodiments are provided to exemplify the present invention, but the present invention is not limited thereto, and appropriate modifications can be made based on the above-described embodiments. For example, each of the above-described embodiments may be used alone, or a combination of two or more of the above-described embodiments may be used.

[0062] As can be seen from the above embodiment, the priority of the first coordination information is equal to the highest priority of the first sidelink information and the second sidelink information, so that the priority of the coordination information can be accurately determined, and when determining whether to transmit or drop the sidelink information based on the priority rule, the priority of sending the collision indication can be ensured to match the priority of the service, so that information related to a high-priority service can be transmitted first.

[0063] <Example of the second aspect> An embodiment of the present invention provides a method for coordination between devices, which is described from the perspective of a first terminal device. The embodiment of the present invention can be used in combination with the embodiment of the first aspect, or can be implemented alone.

[0064] 5 is a diagram illustrating a method for device coordination according to an embodiment of the present invention. As shown in FIG. 5, the method includes the following steps (operations):

[0065] 501: A first terminal device receives first sidelink information from a second terminal device and second sidelink information from a third terminal device; 502: The first terminal device determines, based on the first sidelink information and the second sidelink information, that the first sidelink information and the second sidelink information need to be retransmitted; and The first terminal device transmits second coordination information to the second terminal device to instruct that the first sidelink information needs to be retransmitted, and transmits third coordination information to the third terminal device to instruct that the second sidelink information needs to be retransmitted. Among them, the priority of the second coordination information is equal to the priority of the first sidelink information, and the priority of the third coordination information is equal to the priority of the second sidelink information.

[0066] Note that the above-mentioned FIG. 5 is for exemplarily explaining an embodiment of the present invention, but the present invention is not limited thereto. For example, the execution order between each operation can be appropriately adjusted, or several operations can be increased or decreased. A person skilled in the art is not limited to the description of the above-mentioned FIG. 5, and can perform appropriate modifications based on the above-mentioned content.

[0067] In some embodiments, the device may need to transmit coordination information and other information simultaneously. Here, the other information includes sidelink information and / or uplink information, such as PSFCH, PUSCH, etc., but an exhaustive enumeration is omitted. Due to the limitation of the device capabilities, the device needs to select and transmit M pieces of information from N pieces of information (M < N). The device needs to determine which information to finally transmit based on the priority of the information. The priorities of the sidelink information and the uplink information have already been defined in the standard. How to determine the priority of the coordination information is a problem that needs to be solved.

[0068] In some embodiments, the first SLIC includes first SLIC control information (SCI) and a first Physical Sidelink Shared Channel (PSSCH), where the priority of the first SLIC is equal to the priority indicated by a field in the first SLIC. The second SLIC includes second SLIC control information (SCI) and a second Physical Sidelink Shared Channel (PSSCH), where the priority of the second SLIC is equal to the priority indicated by a field in the second SLIC. For specific fields indicating the priority in the SCI, see the related art.

[0069] In some embodiments, the resources in which the first sidelink information is located and the resources in which the second sidelink information is located at least partially overlap in the time domain. The second terminal device is a target receiving terminal device of the third terminal device, and the third terminal device is a target receiving terminal device of the second terminal device. That is, the second terminal device and the third terminal device are a source and a destination of each other. For example, the second terminal device transmits one PSCCH / PSSCH to the third terminal device, and the third terminal device transmits another PSCCH / PSSCH to the second terminal device.

[0070] 6 is an example diagram of the transmission of coordination information in an embodiment of the present invention. As shown in FIG. 6, device B and device C simultaneously transmit on resource 1 and resource 3 of the same slot. Due to the half-duplex restriction, device B and device C cannot receive the sidelink information transmitted by the other party, i.e., a half-duplex problem occurs.

[0071] By receiving the SCI sent by device B on resource 1 and the SCI sent by device C on resource 3, device A can learn that a half-duplex problem has occurred between devices B and C. Therefore, by sending coordination information B and coordination information C to devices B and C, respectively, device A can notify devices B and C to retransmit.

[0072] Since the retransmission resources (resource 2 and resource 4) of device B and device C can be received by the other party, the half-duplex problem can be avoided. Since coordination information B and coordination information C are used to notify device B and device C to perform retransmission, the priorities of coordination information B and coordination information C are the priorities of the PSSCHs of device B and device C, respectively.

[0073] In some embodiments, the second and third coordination information are carried by a physical sidelink feedback channel (PSFCH), e.g., when coordination information is used to indicate a retransmission, the PSFCH resources can be reused to indicate a NACK.

[0074] In some embodiments, the first terminal device may randomly or pseudo-randomly select and transmit M pieces of coordination information from the N pieces of coordination information, where M is smaller than N and both are positive integers. For specific implementation methods, please refer to the embodiments of the fifth aspect described below.

[0075] In some embodiments, the second terminal device performs unicast, groupcast, or broadcast sidelink communication, i.e., the above-described embodiments can be applied to any unicast, groupcast, or broadcast scenario.

[0076] In some embodiments, the second terminal device performs sidelink communication for the first groupcast, and one or more receiving terminal devices in the first groupcast use the same physical sidelink feedback channel (PSFCH) resource to feed back negative acknowledgements (NACKs). That is, the above embodiments are applicable to groupcast scenarios with HARQ option 1.

[0077] The above-described embodiments are provided to exemplify the present invention, but the present invention is not limited thereto, and appropriate modifications can be made based on the above-described embodiments. For example, each of the above-described embodiments may be used alone, or a combination of two or more of the above-described embodiments may be used.

[0078] As can be seen from the above embodiment, the priority of the second coordination information is equal to the priority of the first sidelink information, and the priority of the third coordination information is equal to the priority of the second sidelink information, so that the priority of the coordination information can be accurately determined, and when determining whether to transmit or drop sidelink information based on the priority rule, the priority of sending collision indication can be ensured to match the priority of the service, so that information related to a high-priority service can be transmitted first.

[0079] <Example of the third aspect> In the embodiments of the present invention, a method for inter-device coordination is provided, which will be described from the perspective of a first terminal device and a second terminal device. The embodiments of the present invention can be used in combination with the embodiments of the first and second aspects, or can be implemented independently.

[0080] How to transmit coordination information for instructing reselection or retransmission is a problem that needs to be solved. A mechanism similar to that for transmitting PSFCH can be used. Specifically, PSFCH resources, such as RBs and sequence (cyclic shift) resources, for carrying coordination information in existing PSFCH slots are additionally configured or pre-configured.

[0081] 7 is an exemplary diagram of a PSFCH in an embodiment of the present invention. As shown in FIG. 7, the PSFCH transmitted by device B is associated with multiple PSFCH resources, namely, a PSFCH indicating ACK, a PSFCH indicating NACK (retransmission), and a PSFCH indicating reselection. The PSFCH indicating ACK / NACK can reuse existing standards. The PSFCH indicating reselection is additionally configured or pre-configured. Note that, regardless of the PSFCH, the method of associating the PSSCH with the PSFCH resource can all reuse existing standards.

[0082] If device A is the destination of device B, after device A receives the PSCCH / PSSCH of device B, it decides to instruct device B to ACK, NACK or reselect, and also transmits a corresponding PSFCH. Even if device C is not the destination of device B, device C can demodulate the PSCCH of device B and find a collision or half-duplex problem occurring between device B and another device (device D), so it decides to instruct device B to reselect or retransmit (NACK), and also transmits a corresponding PSFCH.

[0083] When multiple devices send reselection instructions (or retransmission instructions) to device B, the PSFCHs (including time domain, frequency domain, and code domain resources) they transmit are all the same, thereby forming a co-directional superposition of multiple identical signals and saving the resource overhead of coordination information. Specifically, a device transmits a PSFCH when it needs to send a reselection instruction and does not transmit a PSFCH when it does not need to send a reselection instruction. Therefore, the presence or absence of a PSFCH can indicate whether device B needs to perform resource reselection. Device B can identify the reselection instruction, but cannot identify which device sent the reselection instruction. In fact, the transmission mechanism of the reselection instruction is the same as the transmission mechanism of a NACK in groupcast of HARQ option 1, and both indicate information based on the presence or absence of a signal.

[0084] However, the above scheme may cause ambiguity as to whether device B should perform resource reselection. Considering a groupcast with HARQ option 1, i.e., a groupcast that only feeds back NACK (NACK-only), a device (group member) receiving the groupcast feeds back only NACK, not ACK. Since the PSFCHs for NACK indications transmitted by group members are all the same, a co-directional superposition of multiple identical signals is formed. If device B transmits a groupcast PSSCH, device B can receive both a reselection indication and an ACK indication in the following two scenarios:

[0085] Scenario 1: All group members indicate ACK (ie, do not feed back NACK), and non-group member device A sends a reselection indication to device B.

[0086] FIG. 8 is an exemplary diagram of PSFCH feedback in an embodiment of the present invention. As shown in FIG. 8, device B and device D belong to the same group and can perform groupcast with HARQ option 1. Device A and device C do not belong to the group. Device A can receive the PSCCH / PSSCH of device B and device C and can also feedback a PSFCH (e.g., carrying coordination information) to device B. For example, as shown in FIG. 8, group member device D and other group members all indicate ACK (do not feedback PSFCH). Non-group member device A finds that a collision may occur between the retransmission reserved by device B and device C as shown in FIG. 4, and therefore instructs device B to perform resource reselection. Device B can determine that the ACK and reselection indication appear simultaneously.

[0087] Scenario 2: All group members instruct device B to perform resource reselection. Non-group members do not instruct reselection. Since group members only send reselection instructions and do not send NACKs, device B can determine that ACKs and reselection instructions appear simultaneously.

[0088] 9 is another example diagram of PSFCH feedback in an embodiment of the present invention. As shown in FIG. 9, device B and device D belong to the same group and can perform groupcast with HARQ option 1. Device A and device C do not belong to the same group, and device A can receive the PSCCH / PSSCH of device B and device C. For example, as shown in FIG. 9, group member device D and other group members all indicate reselection, while non-group members do not indicate reselection. Because group members only send reselection indications and do not send NACKs, device B can also determine that ACK and reselection indications appear simultaneously.

[0089] In scenario 1, all group members feedback ACK, so device B does not need to perform retransmission, and there will be no future collision with device C. In scenario 1, device B does not actually need to perform resource reselection, and should process according to the ACK. In scenario 2, none of the group members successfully demodulate, so device B should perform resource reselection and send a retransmission on the reselected resource.

[0090] However, in the above two scenarios, the observation results on the device B side are that both ACK and reselection indication exist, and device B cannot distinguish which scenario the result comes from. Therefore, device B cannot determine whether to process according to ACK or reselection. Incorrect processing may cause device B to perform unnecessary resource reselection and transmission in scenario 1, causing additional interference to other devices, or may cause device B to be unable to send retransmissions continuously in scenario 2, resulting in demodulation failure.

[0091] In view of the above-mentioned problems, the first terminal device (device A and / or device D) will be explained below.

[0092] 10 is a diagram illustrating a method for device coordination according to an embodiment of the present invention. As shown in FIG. 10, the method includes the following steps (operations):

[0093] 1001: A first terminal device receives sidelink information from a second terminal device; and 1002: Depending on whether the first terminal device is the destination terminal device of the second terminal device, the first terminal device sends a reselection instruction to the second terminal device to instruct it to perform resource reselection and / or an acknowledgement (ACK) or non-acknowledgement (NACK) of sidelink information.

[0094] Note that, although the above-described FIG. 10 is used to exemplify an embodiment of the present invention, the present invention is not limited thereto. For example, the execution order of each operation may be appropriately adjusted, or some operations may be added or removed. Those skilled in the art are not limited to the description of the above-described FIG. 10, and may make appropriate modifications based on the above content.

[0095] In some embodiments, when the first terminal device is a target terminal device of the second terminal device and the second terminal device needs to perform resource reselection, it sends both a reselection indication and a non-acknowledgement (NACK) to the second terminal device.

[0096] In this case, when executing the priority rule, the reselection instruction and the non-confirmation are treated as one piece of feedback information, and priority sorting is performed, and the priority of the feedback information is equal to the highest priority among the reselection instruction and the non-confirmation, where priority sorting determines whether to send the information based on the priority, that is, it is equivalent to determining whether to send or drop the information.

[0097] For example, when group member device D shown in Figure 8 or Figure 9 needs to transmit a reselection indication and a NACK at the same time, and device D needs to execute a priority rule to determine which PSFCH to transmit or drop, the reselection indication and the NACK are bundled together and their priorities are sorted. The priority of this bundle is equal to the highest priority of the reselection indication and the NACK. When using the embodiment of the first aspect described above, the priority of the reselection indication is always higher than the priority of the NACK, and in this case, the priority of the bundle is equal to the priority of the reselection indication.

[0098] In some embodiments, when the first terminal device is not the target terminal device of the second terminal device and the second terminal device needs to perform resource reselection, the reselection indication is sent to the second terminal device.

[0099] For example, when non-group member device A in FIG. 8 or FIG. 9 needs to transmit a reselection instruction, it transmits a PSFCH (reselection instruction) to instruct only device B to perform reselection.

[0100] As a result, in the case of scenario 1, ACK and reselection instructions may both appear, so device B performs processing according to ACK, and in the case of scenario 2, NACK and reselection instructions may both appear, so device B performs processing according to reselection. This solves the problem of not being able to determine whether device B will perform reselection.

[0101] In some embodiments, the reselection indication is carried by the physical sidelink feedback channel (PSFCH).

[0102] For example, the slots of the physical sidelink feedback channel carrying the reselection indication may be the same as the slots of the physical sidelink feedback channel carrying the acknowledgment (ACK) or non-acknowledgment (NACK), and the resource blocks (RBs) and / or sequence of the physical sidelink feedback channel carrying the reselection indication may be configured or pre-configured and may be different from the resource blocks (RBs) or sequence of the physical sidelink feedback channel carrying the acknowledgment (ACK) or non-acknowledgment (NACK).

[0103] Also, for example, the slots of the physical sidelink feedback channel carrying the reselection indication may be different from the slots of the physical sidelink feedback channel carrying the acknowledgement (ACK) or non-acknowledgement (NACK).

[0104] In some embodiments, the second terminal device performs sidelink communication of the first groupcast, and the receiving terminal device in the first groupcast uses the same physical sidelink feedback channel resource to feedback the non-acknowledgement, i.e., multiple devices perform groupcast with HARQ option 1 as shown in Figure 8 or Figure 9, but the present invention is not limited thereto.

[0105] In some embodiments, the second terminal device performs unicast, groupcast, or broadcast sidelink communication, i.e., the above-described embodiments can be applied to any unicast, groupcast, or broadcast scenario.

[0106] Below, a further explanation will be given from the side of the second terminal device (device B).

[0107] As shown in FIG. 10, the second terminal device transmits sidelink information; and receives a reselection instruction for instructing resource reselection and / or an acknowledgement (ACK) or non-acknowledgement (NACK) of the sidelink information transmitted by one or more first terminal devices.

[0108] In some embodiments, the second terminal device performs resource reselection when it determines that there is a no acknowledgement (NACK) or discontinuous transmission (DTX) and receives a reselection indication.

[0109] In some embodiments, if the second terminal device determines that the sidelink information has been correctly received when it determines that the sidelink information is an acknowledgment (ACK), then if the first terminal device determines that the second terminal device will send an acknowledgment (ACK) to the second terminal device and the ACK transmission is not canceled due to the priority rule, the first terminal device can instruct the second terminal device that there is no need to perform resource reselection.

[0110] In some embodiments, the second terminal device determines that the sidelink information was not received correctly if it determines that there is a non-acknowledgement (NACK) or discontinuous transmission (DTX) but does not receive a reselection indication.

[0111] For example, when device B shown in FIG. 8 or FIG. 9 judges whether it is ACK or NACK according to the existing standard, and if the judgment result is ACK, regardless of whether a reselection instruction exists, device B performs all processing according to ACK, for example, performs operations such as flushing the buffer; if the judgment result is NACK and no reselection instruction is received, device B performs processing according to NACK, for example, sends a retransmission; if the judgment result is NACK and a reselection instruction is received, device B performs resource reselection.

[0112] As a result, in the case of scenario 1, ACK and reselection indication may both appear, so device B can perform processing according to ACK, and in the case of scenario 2, NACK and reselection indication may both appear, so device B can perform processing according to reselection, thus solving the problem of device B being unable to determine whether to perform reselection.

[0113] The above-described embodiments are provided to exemplify the present invention, but the present invention is not limited thereto, and appropriate modifications can be made based on the above-described embodiments. For example, each of the above-described embodiments may be used alone, or a combination of two or more of the above-described embodiments may be used.

[0114] As can be seen from the above embodiment, the first terminal device transmits a reselection indication and / or an ACK / NACK to the second terminal device depending on whether it is the destination terminal device of the second terminal device, thereby avoiding ambiguity that occurs when a device receiving the reselection indication distinguishes between the ACK / NACK and the reselection indication, and improving the reliability of sidelink transmission.

[0115] <Example of the fourth aspect> In the embodiments of the present invention, an inter-device coordination method is provided, and will be described from the perspective of a first terminal device and a second terminal device. The embodiments of the present invention can be used in combination with the embodiments of the first and second aspects, or can be implemented independently. The difference from the embodiment of the third aspect is that the embodiment of the fourth aspect makes a decision based on resources. Note that descriptions of the same content as the embodiment of the third aspect will be omitted.

[0116] Hereinafter, still taking the scenarios of FIGS. 8 and 9 as an example, the first terminal device (device A and / or device D) will be explained first.

[0117] 11 is a diagram illustrating a method for device coordination in an embodiment of the present invention. As shown in FIG. 11, the method includes the following steps:

[0118] 1101: A first terminal device receives sidelink information from a second terminal device; and 1102: Depending on whether the first terminal device is a destination terminal device of the second terminal device, a reselection instruction is sent to the second terminal device to instruct it to perform resource reselection using the first resource or the second resource.

[0119] Note that, although the above-mentioned FIG. 11 is used to exemplify an embodiment of the present invention, the present invention is not limited thereto. For example, the execution order of each operation may be appropriately adjusted, or some operations may be added or removed. Those skilled in the art are not limited to the description of the above-mentioned FIG. 11, and may make appropriate modifications based on the above content.

[0120] In some embodiments, when the first terminal device is a destination terminal device of the second terminal device and the second terminal device needs to perform resource reselection, it sends a reselection instruction to the second terminal device using the first resource.

[0121] In some embodiments, the first resource is a physical sidelink feedback channel (PSFCH) resource.

[0122] For example, the slot of the first resource carrying the reselection indication may be the same as the slot of the physical sidelink feedback channel carrying the acknowledgment (ACK) or non-acknowledgment (NACK), and the resource blocks (RBs) and / or sequence of the first resource carrying the reselection indication may be configured or pre-configured and may be different from the resource blocks (RBs) or sequence of the physical sidelink feedback channel carrying the acknowledgment (ACK) or non-acknowledgment (NACK).

[0123] Also, for example, the slots of the first resource carrying the reselection indication may be different from the slots of the physical sidelink feedback channel carrying the acknowledgement (ACK) or non-acknowledgement (NACK).

[0124] In some embodiments, when the first terminal device is not the target terminal device of the second terminal device and the second terminal device needs to perform resource reselection, a reselection instruction is sent to the second terminal device using the second resource.

[0125] In some embodiments, the second resource is different from the first resource.

[0126] In some embodiments, the second resource is a physical sidelink feedback channel (PSFCH) resource.

[0127] For example, the slot of the second resource carrying the reselection indication may be the same as the slot of the physical sidelink feedback channel carrying the acknowledgment (ACK) or non-acknowledgment (NACK), and the resource blocks (RBs) and / or sequence of the second resource carrying the reselection indication may be configured or pre-configured and may be different from the resource blocks (RBs) or sequence of the physical sidelink feedback channel carrying the acknowledgment (ACK) or non-acknowledgment (NACK).

[0128] Also, for example, the slots of the second resource carrying the reselection indication may be different from the slots of the physical sidelink feedback channel carrying the acknowledgement (ACK) or non-acknowledgement (NACK).

[0129] In some embodiments, when a first terminal device is a destination terminal device of a second terminal device and the second terminal device needs to perform resource reselection, the first terminal device sends a reselection instruction to the second terminal device using the first resource and skips sending a NACK to the second terminal device, i.e., does not send a NACK to the second terminal device.

[0130] For example, when it is determined that the first terminal device is the receiving destination of the second terminal device and that a reselection instruction needs to be sent, this means that the demodulation result of the first terminal device is a NACK. At this time, the first terminal device may not send a NACK but may only send a reselection instruction. This is because, when the second terminal device receives a reselection instruction from the receiving destination, it can perform resource reselection. Conversely, when the demodulation result of the first terminal device is an ACK, it can be determined that there is no need to send a reselection instruction to the second terminal device. This is because, after the second terminal device receives an ACK, there is no need to send a retransmission, and therefore no need to perform reselection. At this time, the first terminal device can simply send an ACK according to the conventional method.

[0131] 12 is another exemplary diagram of a PSFCH in an embodiment of the present invention. As shown in FIG. 12, a receiving device of device B uses a first PSFCH to transmit a reselection instruction, and a non-receiving device of device B uses a second PSFCH to transmit a reselection instruction. Therefore, device B can know whether the reselection is instructed by its own receiving device or by a device other than its own receiving device based on the first PSFCH and the second PSFCH.

[0132] As a result, in scenario 1, device B can know that all receiving devices have instructed ACK (not instructing reselection) and that non-receiving devices have instructed reselection (i.e., there are non-receiving devices instructing reselection), so device B can perform processing in accordance with ACK, and in scenario 2, device B can know that receiving devices have instructed reselection (i.e., there are receiving devices instructing reselection), so device B can perform processing in accordance with reselection. Thus, the above-mentioned problem of device B being unable to determine whether to perform reselection can be solved.

[0133] In some embodiments, the first resource and the second resource are physical sidelink feedback channel (PSFCH) resources, the slot of the first resource is the same as the slot of the second resource, the resource blocks (RBs) and / or sequences of the first resource and the second resource are configured or pre-configured, and the resource blocks (RBs) or sequences of the first resource and the second resource are different.

[0134] For example, the first PSFCH and the second PSFCH are transmitted using different RB resources, and multiple first PSFCHs transmitted by different receiving devices are the same, so that co-directional superposition can be formed in the same time-frequency resource, and multiple second PSFCHs transmitted by different non-receiving devices are the same, so that co-directional superposition can be formed in the same time-frequency resource.

[0135] In some embodiments, the second terminal device performs sidelink communication of the first groupcast, and the receiving terminal device in the first groupcast uses the same physical sidelink feedback channel resource to feedback the non-acknowledgement, i.e., multiple devices perform groupcast with HARQ option 1 as shown in Figure 8 or Figure 9, but the present invention is not limited thereto.

[0136] In some embodiments, the second terminal device performs unicast, groupcast, or broadcast sidelink communication, i.e., the above-described embodiments can be applied to any unicast, groupcast, or broadcast scenario.

[0137] Below, a further explanation will be given from the side of the second terminal device (device B).

[0138] As shown in FIG. 11, the second terminal device transmits sidelink information; and receives an acknowledgement (ACK) or non-acknowledgement (NACK) of the sidelink information transmitted by one or more first terminal devices, and / or a reselection instruction transmitted by the first terminal device using the first resource and / or the second resource to instruct resource reselection.

[0139] In some embodiments, the second terminal device determines that the sidelink information has already been received correctly if it determines that it is an acknowledgment (ACK) and does not receive a reselection indication on the first resource.

[0140] In some embodiments, the second terminal device determines that the sidelink information was not received correctly if it determines that there is a non-acknowledgement (NACK) or discontinuous transmission (DTX) and does not receive a reselection indication for both the first and second resources.

[0141] In some embodiments, the second terminal device performs resource reselection when it determines that the request is a confirmation and receives a reselection instruction on the first resource, or when it determines that the request is a non-confirmation or DTX and receives a reselection instruction on the first resource or the second resource. Thus, when the first terminal device is the target terminal device of the second terminal device and the second terminal device needs to perform resource reselection, the first terminal device sends a reselection instruction to the second terminal device using the first resource and skips sending a NACK to the second terminal device.

[0142] As a result, in scenario 1, device B can know that all receiving devices have instructed ACK (not reselection) and that non-receiving devices have instructed reselection, so device B can perform processing in accordance with ACK, and in scenario 2, device B can know that receiving devices have instructed reselection, so device B can perform processing in accordance with reselection. Thus, the above-mentioned problem of device B not knowing whether to perform reselection can be solved.

[0143] The above-described embodiments are provided to exemplify the present invention, but the present invention is not limited thereto, and appropriate modifications can be made based on the above-described embodiments. For example, each of the above-described embodiments may be used alone, or a combination of two or more of the above-described embodiments may be used.

[0144] As can be seen from the above embodiment, the first terminal device transmits a reselection instruction to the second terminal device using the first resource or the second resource depending on whether it is the destination terminal device of the second terminal device, thereby avoiding ambiguity that occurs when a device receiving the reselection instruction distinguishes between an ACK / NACK and a reselection instruction, thereby improving the reliability of sidelink transmission.

[0145] <Example of the fifth aspect> In the embodiments of the present invention, an inter-device coordination method is provided, and will be described from the perspective of a first terminal device and a second terminal device. The embodiments of the present invention can be used in combination with the embodiments of the first to fourth aspects, or can be implemented independently. Note that descriptions of the same content as the embodiments of the first to fourth aspects will be omitted.

[0146] In some embodiments, when the first terminal device determines that it will send an acknowledgement (ACK) to the second terminal device and there is no cancellation of the ACK transmission due to priority rules, the first terminal device instructs the second terminal device that there is no need to perform resource reselection.

[0147] For example, the slot for instructing whether to perform resource reselection is located in the same slot as the slot for transmitting the ACK / NACK, or the slot for instructing whether to perform resource reselection is located in a slot different from the slot for transmitting the ACK / NACK, for example, the slot for instructing whether to perform resource reselection is located in a slot after the slot for transmitting the ACK / NACK.

[0148] For non-first groupcast sidelink communication performed by the second terminal device, if the first terminal device determines that it will send an ACK to the second terminal device and the ACK transmission is not canceled due to the priority rule, the first terminal device instructs the second terminal device that there is no need to perform resource reselection (e.g., does not send a resource reselection instruction); otherwise (including when the first terminal device sends a NACK to the second terminal device and / or the transmission of the ACK or NACK is canceled due to the priority rule), the first terminal device instructs the second terminal device whether to perform resource reselection according to the actual situation.

[0149] According to the priority rule, the terminal device can transmit a physical channel or signal with a high priority, but not transmit a physical channel or signal with a low priority. For specific priority rules, see Section 16.2.4 of TS38.213. Here, non-primary groupcast includes unicast with ACK / NACK enabled and groupcast with HARQ option 2.

[0150] For the sidelink communication of the first groupcast performed by the second terminal device, when the first terminal device determines to send an ACK to the second terminal device, the first terminal device does not send any signal using the PSFCH, and therefore the ACK transmission is not canceled according to the priority rule. In this case, the first terminal device instructs the second terminal device that there is no need to perform resource reselection; otherwise (including when the first terminal device sends a NACK to the second terminal device and / or the NACK transmission is canceled according to the priority rule), the first terminal device instructs the second terminal device whether to perform resource reselection according to the actual situation.

[0151] Tables 1 and 2 summarize the relationship between the ACK / NACK of the first terminal device and the reselection instruction when the second terminal device performs sidelink communication of non-first groupcast and first groupcast, respectively.

[0152] Table 1 shows the cases of non-first group casts.

[0153] [Table 1] Table 2 shows the case of the first group cast.

[0154] [Table 2] The methods shown in Tables 1 and 2 have the following advantageous effects: after the first terminal device sends or indicates ACK, the second terminal device does not retransmit, so the first terminal device does not need to send a reselection indication, which can save power and avoid the occurrence of drops due to priority rules, specifically, avoid dropping the transmission or reception of other useful physical channels or signals due to the transmission of unnecessary (useless) reselection indications.

[0155] In the case of a non-first groupcast, after canceling the ACK or NACK transmission, the second terminal device can determine that it is DTX, and can still perform retransmission, allowing the first terminal device to instruct whether to perform resource reselection, thereby further avoiding collisions during retransmission by the second terminal device.

[0156] In the case of the first groupcast, after canceling the NACK transmission, the second terminal device may mistakenly determine that it is an ACK and stop retransmission. For example, if one group member device that should originally transmit a NACK cancels the NACK transmission based on a priority rule and all other group member devices instruct the second terminal device to transmit an ACK, the second terminal device may mistakenly determine that it is an ACK. By having the first terminal device instruct whether to perform resource reselection, there is still a chance that the second terminal device will know that retransmission and resource reselection are necessary. For example, even if the second terminal device mistakenly determines that it is an ACK, the second terminal can still perform retransmission and resource reselection when it receives a reselection instruction from a group member.

[0157] The methods shown in Tables 1 and 2 can be applied to the embodiments of each of the above-mentioned aspects. For example, in the embodiment of the third aspect, the last line in Table 2, "instruct whether to perform resource reselection," may be changed to "instruct whether to perform resource reselection, or instruct not to perform resource reselection." This is because the second terminal device in the embodiment of the third aspect does not perform resource reselection after determining that the signal is ACK. Therefore, the first terminal device may directly instruct not to perform resource reselection.

[0158] Below, a further explanation will be given from the side of the second terminal device (device B).

[0159] As shown in FIG. 11, the second terminal device transmits sidelink information; and receives an acknowledgement (ACK) or non-acknowledgement (NACK) of the sidelink information transmitted by one or more first terminal devices, and / or a reselection instruction transmitted by the first terminal device using the first resource and / or the second resource to instruct resource reselection.

[0160] In some embodiments, if the second terminal device determines that the sidelink information has been correctly received when it determines that the ACK is an acknowledgment and does not receive a reselection instruction on the first resource, then the first terminal device can instruct the second terminal device that it does not need to perform resource reselection when it determines that the first terminal device will send an acknowledgment to the second terminal and the ACK transmission is not canceled according to the priority rule.

[0161] In some embodiments, the second terminal device determines that the sidelink information was not received correctly if it determines that there is a no-acknowledgement (NACK) or discontinuous transmission (DTX) and does not receive a reselection indication on either the first resource or the second resource.

[0162] In some embodiments, the second terminal device performs resource reselection when it determines that the second terminal device is an acknowledgment and receives a reselection instruction on the first resource, or when it determines that the second terminal device is a non-acknowledgment or DTX and receives a reselection instruction on the first resource or the second resource. Thus, when the first terminal device determines that it will send an acknowledgment (ACK) to the second terminal device and the ACK transmission is not canceled according to the priority rule, the first terminal device can instruct the second terminal device that it does not need to perform resource reselection.

[0163] As a result, in scenario 1, device B can know that all receiving devices have instructed ACK (not reselection) and that non-receiving devices have instructed reselection, so device B can perform processing in accordance with the ACK. Also, in scenario 2, device B can know that receiving devices have instructed reselection, so device B can perform processing in accordance with the reselection. This solves the problem of device B not knowing whether to perform reselection, as described above.

[0164] The above-described embodiments are provided to exemplify the present invention, but the present invention is not limited thereto, and appropriate modifications can be made based on the above-described embodiments. For example, each of the above-described embodiments may be used alone, or a combination of two or more of the above-described embodiments may be used.

[0165] As can be seen from the above embodiment, after the first terminal device sends or indicates ACK, the second terminal device does not retransmit, so the first terminal device does not need to send a reselection indication, which can save power and also avoid the occurrence of drops due to priority rules.

[0166] <Example of the sixth aspect> In the present embodiment, a method for coordination between devices is provided, and will be described from the perspective of a first terminal device. The present embodiment may be used in combination with the embodiments of the first to fifth aspects, or may be implemented alone.

[0167] As shown in Figure 6, a half-duplex problem may occur between devices B and C. If device A finds that a half-duplex problem occurs between devices B and C, device A can avoid the half-duplex problem by sending a retransmission or reselection instruction to devices B and C to notify them to retransmit or reselect.

[0168] 13 is an example diagram of transmission of coordination information in an embodiment of the present invention, and will be described using groupcast of HARQ option 1 as an example. As shown in FIG. 13, in the same slot in which group member device B transmits groupcast, group member device C also simultaneously transmits groupcast, so device B and device C cannot receive each other's transmitted information and do not feed back ACK / NACK. Also, assume that the PSSCHs of device B and device C can be successfully demodulated by other group member devices in the group. In this case, if there is no inter-device coordination, device B and device C may determine that an ACK has occurred and therefore stop subsequent retransmissions.

[0169] When devices coordinate, group member device A can detect a half-duplex problem by receiving the PSCCH / PSSCH of device B and device C. Even if device A can accurately demodulate the PSSCH of device B and device C, device A transmits a NACK on the PSFCH_B and PSFCH_C resources associated with device B and device C, respectively. Devices B and C can then perform a retransmission upon receiving the NACK. Since the retransmission does not cause a half-duplex problem, there is a chance that the retransmission will be correctly received by device C and device B. This method can solve the half-duplex problem, but it requires device A to simultaneously transmit multiple PSFCHs (PSFCH_B and PSFCH_C) in the same slot.

[0170] For the solution of the half-duplex problem, the device needs to transmit N PSFCHs simultaneously. However, due to the limitation of the device capabilities, assume that the device can only transmit M (M < N) PSFCHs simultaneously. In the standard, a priority rule is defined for such a case, and M PSFCHs with relatively high priorities are transmitted. However, thereby, only the half-duplex problem of the high-priority PSSCH can be solved by retransmission, while the half-duplex problem of the low-priority PSSCH still cannot be solved.

[0171] FIG. 14 is another exemplary diagram of the transmission of coordination information in an embodiment of the present invention, and assume that the scenario is the same as that in FIG. 13. Assume that device A can transmit only one PSFCH, and the PSSCH (PSFCH) priority of device B is higher than that of device C. In this case, device A transmits only PSFCH_B to instruct device B to retransmit. Even if other group member devices other than device A also discover the half-duplex problem, according to the existing priority rule, other devices can only transmit a PSFCH to device B to indicate a NACK. Therefore, the PSSCH of device B can be recovered by retransmission, while the PSSCH of device C cannot be recovered.

[0172] In some embodiments, the first terminal device randomly or pseudo-randomly selects and transmits M pieces of coordination information from N pieces of coordination information, where M is smaller than N, and both are positive integers.

[0173] For example, when a device needs to indicate the existence of a half-duplex problem or needs to instruct retransmission by selecting and transmitting M (M < N) pieces of coordination information from N pieces of coordination information, the device randomly or pseudo-randomly selects and transmits the M pieces of coordination information. The above-mentioned coordination information can be carried and transmitted by PSFCH or others. Thereby, by different devices transmitting different M pieces of coordination information, the probability of indicating all half-duplex problems can be increased.

[0174] FIG. 15 is another exemplary diagram of the transmission of coordination information in an embodiment of the present invention, assuming that the scenario is the same as that in FIGS. 13 and 14. As shown in FIG. 15, assume that both device A and device D have discovered all half-duplex problems. When device A transmits only one PSFCH to device B and device D transmits only one PSFCH to device C, both device B and device C can recover from the half-duplex problem by performing subsequent retransmissions.

[0175] The above transmission of the retransmission instruction is due to the occurrence of a half-duplex problem, but the transmission of the retransmission instruction can be by NACK. For example, when device A needs to select and transmit M NACKs (M < N) from N NACKs, device A can also select and transmit the M NACKs in a random or pseudo-random manner.

[0176] In some embodiments, the second terminal device performs unicast, groupcast or broadcast sidelink communication. That is, the above embodiments can be applied to any scenario of unicast, groupcast or broadcast.

[0177] In some embodiments, the second terminal device performs sidelink communication of a first groupcast, and in the first groupcast, the receiving terminal device feeds back a non-acknowledgment (NACK) using the same physical sidelink feedback channel (PSFCH) resource. That is, the above embodiments can be applied to the scenario of groupcast with HARQ option 1.

[0178] The above embodiments are for exemplarily explaining the embodiments of the present invention, but the present invention is not limited thereto, and appropriate modifications can also be made based on the above embodiments. For example, the above embodiments can be used alone, or a plurality of the above embodiments can be combined and used.

[0179] As can be seen from the above embodiment, the first terminal device randomly or pseudo-randomly selects and transmits M pieces of coordination information from N pieces of coordination information, so that when performing inter-device coordination, the coordination device can avoid transmitting coordination information only to devices with high-priority tasks, thereby preventing devices with low-priority tasks from being unable to obtain device coordination.

[0180] <Example of the seventh aspect> In an embodiment of the present invention, a method for coordination between devices is provided, and will be described from the perspective of a first terminal device. The embodiment of the present invention may be used in conjunction with the embodiments of the first to sixth aspects, or may be implemented alone.

[0181] If any device can send coordination information to indicate retransmission or reselection, the coordination information is not accurate enough.

[0182] 16 is an example diagram of transmission of coordination information in an embodiment of the present invention. For example, as shown in FIG. 16, device A is not a destination of devices B and C, but device A finds that there is a collision problem between devices B and C as shown in FIG. 4, and therefore notifies device B to perform resource reselection.

[0183] However, the distance between the receiving devices E and D of devices B and C may be quite far (large), and the actual interference (collision) between devices E and D may be quite small. In such a case, devices E and D may be able to achieve accurate demodulation, and device B may not actually need to perform resource reselection.

[0184] To solve this problem, restrictions may be placed on the devices that can transmit coordination information.

[0185] In some embodiments, the first terminal device receives first sidelink information from the second terminal device and second sidelink information from the third terminal device; the first terminal device determines based on the first sidelink information and the second sidelink information that first resources reserved by the first sidelink information need to be reselected; and When the first terminal device is a target receiving terminal device of the second terminal device, or when the first terminal device is not a target receiving terminal device of the second terminal device but is a target receiving terminal device of a third terminal device, the first terminal device sends first coordination information to the second terminal device to indicate that the first resource needs to be reselected.

[0186] 17 is another exemplary diagram of transmission of coordination information in an embodiment of the present invention. For example, as shown in FIG. 17, if device A finds that a collision may occur between device B and device C, only when device A is the destination of device C, device A can transmit coordination information to device B to notify device B to perform resource reselection. Since device A is the destination of device C and the collision observed by device A at this time is a real collision that may occur, transmission of inaccurate coordination information can be avoided.

[0187] In some embodiments, the second terminal device performs unicast, groupcast, or broadcast sidelink communication, i.e., the above-described embodiments can be applied to any unicast, groupcast, or broadcast scenario.

[0188] In some embodiments, the second terminal device performs sidelink communication for the first groupcast, and in the first groupcast, the receiving terminal device feeds back a negative acknowledgement (NACK) using the same physical sidelink feedback channel (PSFCH) resource, i.e., the above-described embodiments are applicable to groupcast scenarios for HARQ option 1.

[0189] The above-described embodiments are provided to exemplify the present invention, but the present invention is not limited thereto, and appropriate modifications can be made based on the above-described embodiments. For example, each of the above-described embodiments may be used alone, or a combination of two or more of the above-described embodiments may be used.

[0190] As can be seen from the above embodiments, when the first terminal device is the intended receiving terminal device of the second terminal device, or when the first terminal device is not the intended receiving terminal device of the second terminal device but is the intended receiving terminal device of the third terminal device, the first terminal device sends first coordination information to the second terminal device to indicate that the first resource needs to be reselected, thereby avoiding the transmission of inaccurate coordination information and improving the reliability of sidelink transmission.

[0191] <Example of the eighth aspect> In an embodiment of the present invention, an inter-device coordination device is provided. The device may be, for example, a terminal device (e.g., the first terminal device described above), or may be one or more components or assemblies provided in the terminal device. Note that descriptions of the same content as in the embodiments of the first to seventh aspects will be omitted.

[0192] 18 is a diagram illustrating an inter-device coordination device in an embodiment of the present invention. As shown in FIG. 18, the inter-device coordination device 1800 includes the following:

[0193] A receiving unit 1801: receives first sidelink information from a second terminal device and second sidelink information from a third terminal device; a determining unit 1802: determining, based on the first sidelink information and the second sidelink information, that a first resource reserved by the first sidelink information needs to be reselected; and a sending unit 1803: sending first coordination information to the second terminal device to indicate that the first resource needs to be reselected, where the priority of the first coordination information is equal to the highest priority of the first sidelink information and the second sidelink information.

[0194] In some embodiments, the first SLI comprises first SL control information and a first physical SL shared channel, the priority of the first SLI being equal to the priority indicated by a field in the first SL control information, and the second SLI comprises second SL control information and a second physical SL shared channel, the priority of the second SLI being equal to the priority indicated by a field in the second SL control information.

[0195] In some embodiments, the first resources reserved by the first sidelink control information and the second resources reserved by the second sidelink control information at least partially overlap in the time domain and the frequency domain.

[0196] In some embodiments, the first coordination information is carried by a physical sidelink feedback channel.

[0197] In some embodiments, the first terminal is the intended receiving terminal of the second terminal, or the first terminal is not the intended receiving terminal of the second terminal, but the first terminal is the intended receiving terminal of a third terminal.

[0198] In some embodiments, the second terminal device performs unicast, groupcast, or broadcast sidelink communications.

[0199] In some embodiments, the determining unit 1802 is further adapted to determine, based on the first and second sidelink information, that the first and second sidelink information need to be retransmitted.

[0200] The transmitting unit 1803 is further used to: indicate second coordination information to a second terminal device to indicate that the first sidelink information needs to be retransmitted; and transmit third coordination information to a third terminal device to indicate that the second sidelink information needs to be retransmitted, where the priority of the second coordination information is equal to the priority of the first sidelink information and the priority of the third coordination information is equal to the priority of the second sidelink information.

[0201] In some embodiments, the first SLI comprises first SL control information and a first physical SL shared channel, the priority of the first SLI being equal to the priority indicated by a field in the first SL control information, and the second SLI comprises second SL control information and a second physical SL shared channel, the priority of the second SLI being equal to the priority indicated by a field in the second SL control information.

[0202] In some embodiments, the resources in which the first sidelink information is located and the resources in which the second sidelink information is located at least partially overlap in the time domain.

[0203] In some embodiments, the second terminal is an intended recipient terminal for the third terminal, and the third terminal is an intended recipient terminal for the second terminal.

[0204] In some embodiments, the second coordination information and the third coordination information are carried by a physical sidelink feedback channel.

[0205] In some embodiments, the transmitting unit 1803 is further configured to randomly or pseudo-randomly select and transmit M pieces of coordination information from N pieces of coordination information, where M is less than N and both are positive integers.

[0206] The above-described embodiments are provided to exemplify the present invention, but the present invention is not limited thereto, and appropriate modifications can be made based on the above-described embodiments. For example, each of the above-described embodiments may be used alone, or a combination of two or more of the above-described embodiments may be used.

[0207] Although the components and modules related to the present invention have been described above, the present invention is not limited to these. The inter-device coordination device 1800 may further include other components or modules, and the specific contents of these components or modules can be found in the related art.

[0208] 18 shows only the connection relationships or signal directions between each component or module, but it should be understood by those skilled in the art that various related technologies, such as bus connections, may be employed. Each of the components or modules described above may be realized by hardware, such as a processor, a memory, a transmitter, a receiver, etc., but the implementation of the present invention is not limited thereto.

[0209] As can be seen from the above embodiments, the priority of coordination information can be accurately determined, and when determining whether to transmit or drop sidelink information based on the priority rule, the priority of sending collision indication can be ensured to match the priority of the service, and information related to high-priority services can be ensured to be transmitted preferentially.

[0210] <Example of the ninth aspect> In an embodiment of the present invention, an inter-device coordination device is provided. The device may be, for example, a terminal device (e.g., the first terminal device described above), or may be one or more components or assemblies provided in the terminal device. Note that descriptions of the same content as in the embodiments of the first to eighth aspects will be omitted.

[0211] 19 is a diagram illustrating an apparatus for inter-device coordination according to an embodiment of the present invention. As shown in FIG. 19, an apparatus for inter-device coordination 1900 includes a receiving unit 1901 and a transmitting unit 1902.

[0212] In some embodiments, the receiving unit 1901 receives sidelink information from the second terminal device, and the transmitting unit 1902 transmits a reselection instruction to the second terminal device to instruct it to perform resource reselection and / or a confirmation or non-confirmation of the sidelink information depending on whether the first terminal device is the destination terminal device of the second terminal device.

[0213] In some embodiments, when the first terminal device is a target terminal device of the second terminal device and the second terminal device needs to perform resource reselection, it sends both a reselection indication and a non-confirmation to the second terminal device.

[0214] In some embodiments, when executing the priority rule, the reselection instruction and the non-confirmation are treated as one feedback information, and the priority is sorted, and the priority of the feedback information is equal to the highest priority of the reselection instruction and the non-confirmation.

[0215] In some embodiments, when the first terminal device is not the target terminal device of the second terminal device and the second terminal device needs to perform resource reselection, the reselection indication is sent to the second terminal device.

[0216] In some embodiments, the reselection indication is carried by a physical sidelink feedback channel, the slot of the physical sidelink feedback channel carrying the reselection indication is the same as the slot of the physical sidelink feedback channel carrying the acknowledgment or non-acknowledgment, the resource blocks and / or sequence of the physical sidelink feedback channel carrying the reselection indication are configured or pre-configured and are different from the resource blocks or sequence of the physical sidelink feedback channel carrying the acknowledgment or non-acknowledgment, or the slot of the physical sidelink feedback channel carrying the reselection indication is different from the slot of the physical sidelink feedback channel carrying the acknowledgment or non-acknowledgment.

[0217] In some embodiments, the receiving unit 1901 receives sidelink information from the second terminal device, and the transmitting unit 1902 transmits a reselection instruction to instruct the second terminal device to perform resource reselection using the first resource or the second resource depending on whether the first terminal device is a destination terminal device of the second terminal device.

[0218] In some embodiments, when the first terminal device is a destination terminal device of the second terminal device and the second terminal device needs to perform resource reselection, it sends a reselection instruction to the second terminal device using the first resource.

[0219] In some embodiments, when the first terminal device is not the target terminal device of the second terminal device and the second terminal device needs to perform resource reselection, a reselection instruction is sent to the second terminal device using the second resource.

[0220] The above-described embodiments are provided to exemplify the present invention, but the present invention is not limited thereto, and appropriate modifications can be made based on the above-described embodiments. For example, each of the above-described embodiments may be used alone, or a combination of two or more of the above-described embodiments may be used.

[0221] Although the components and modules related to the present invention have been described above, the present invention is not limited to these. The inter-device coordination device 1900 may further include other components or modules, and the specific contents of these components or modules can be found in the related art.

[0222] 19 only shows the connection relationships or signal directions between each component or module, but it should be understood by those skilled in the art that various related technologies, such as bus connections, may also be employed. Each of the components or modules described above may be realized by hardware, such as a processor, memory, transmitter, or receiver, but the implementation of the present invention is not limited thereto.

[0223] As can be seen from the above embodiments, it is possible to avoid ambiguity that occurs when a device receiving a reselection indication distinguishes between an ACK / NACK and a reselection indication, thereby improving the reliability of sidelink transmission.

[0224] <Example of the tenth aspect> An embodiment of the present invention further provides a communication system, which can be seen from FIG. 1, and the description of the same contents as those of the embodiments of the first to ninth aspects will be omitted.

[0225] In some embodiments, the communication system 100 may include at least the following:

[0226] a first terminal device: receiving first sidelink information from a second terminal device and second sidelink information from a third terminal device; determining, based on the first sidelink information and the second sidelink information, that a first resource reserved by the first sidelink information needs to be reselected; and sending first coordination information to the second terminal device to indicate that the first resource needs to be reselected, wherein the priority of the first coordination information is equal to the highest priority of the first sidelink information and the second sidelink information.

[0227] In some embodiments, the communication system 100 may include at least the following:

[0228] a first terminal device: receives first sidelink information from a second terminal device and second sidelink information from a third terminal device; determines based on the first sidelink information and the second sidelink information that the first sidelink information and the second sidelink information need to be retransmitted; and sends second coordination information to the second terminal device to indicate that the first sidelink information needs to be retransmitted, and sends third coordination information to the third terminal device to indicate that the second sidelink information needs to be retransmitted, where the priority of the second coordination information is equal to that of the first sidelink information and the priority of the third coordination information is equal to that of the second sidelink information.

[0229] In some embodiments, the communication system 100 may include at least the following:

[0230] A first terminal device receives sidelink information from a second terminal device, and depending on whether the second terminal device is a destination terminal device, sends a reselection instruction to the second terminal device to instruct it to perform resource reselection and / or an acknowledgement (ACK) or non-acknowledgement (NACK) of the sidelink information; and Second terminal device: Transmits sidelink information and receives a reselection instruction and / or an acknowledgement (ACK) or non-acknowledgement (NACK) of the sidelink information transmitted by one or more first terminal devices to instruct resource reselection.

[0231] In some embodiments, the communication system 100 may include at least the following:

[0232] A first terminal device: receives sidelink information from a second terminal device, and sends a reselection instruction to the second terminal device to instruct the second terminal device to perform resource reselection using a first resource or a second resource depending on whether the second terminal device is a destination terminal device; and Second terminal device: Transmits sidelink information and receives one or more acknowledgements (ACK) or non-acknowledgements (NACK) of sidelink information transmitted by the first terminal device, and / or a reselection instruction for instructing the first terminal device to perform resource reselection, which the first terminal device transmits using the first resource and / or the second resource.

[0233] In some embodiments, the communication system 100 may include at least the following:

[0234] First terminal device: randomly or pseudo-randomly selects and transmits M pieces of coordination information from N pieces of coordination information, where M is smaller than N and both are positive integers.

[0235] In some embodiments, the communication system 100 may include at least the following:

[0236] A first terminal device receives first sidelink information from a second terminal device and second sidelink information from a third terminal device; and determines, based on the first sidelink information and the second sidelink information, that a first resource reserved by the first sidelink information needs to be reselected; and, if the first terminal device is an intended receiving terminal device of the second terminal device, or if the first terminal device is not an intended receiving terminal device of the second terminal device but is an intended receiving terminal device of the third terminal device, the first terminal device sends first coordination information to the second terminal device to indicate that the first resource needs to be reselected.

[0237] In an embodiment of the present invention, a network device is further provided, which may be, for example, a base station, but the present invention is not limited thereto and may be other network devices.

[0238] 20 is a block diagram of a network device according to an embodiment of the present invention. As shown in FIG. 20, the network device 2000 may include a processor 2010 (e.g., a central processing unit (CPU)) and a memory 2020, which is connected to the processor 2010. The memory 2020 can store various data and can also store a program 2030 for information processing, and can execute the program 2030 under the control of the processor 2010.

[0239] 20, the network device 2000 may further include a transceiver 2040, an antenna 2050, etc., and the functions of these components are the same as those of the prior art, so detailed description thereof will be omitted here. Note that the network device 2000 does not need to include all the components shown in Fig. 20. The network device 2000 may also include components not shown in Fig. 20, but reference can be made to the prior art for such components.

[0240] Although a terminal device is further provided in the embodiment of the present invention, the present invention is not limited thereto and may be other devices.

[0241] 21 is a diagram illustrating a terminal device according to an embodiment of the present invention. As shown in FIG. 21, the terminal device 2100 may include a processor 2110 and a memory 2120, where the memory 2120 stores data and programs and is connected to the processor 2110. Note that this diagram is merely an example, and other types of structures may be used to supplement or replace the structures to achieve telecommunications or other functions.

[0242] For example, the processor 2110 may be configured to execute a program to implement the inter-device coordination method described in the embodiments of the first aspect. For example, the processor 2110 may be configured to perform the following controls: receive first sidelink information from a second terminal device and second sidelink information from a third terminal device; determine, based on the first sidelink information and the second sidelink information, that first resources reserved by the first sidelink information need to be reselected; and send first coordination information to the second terminal device, indicating that the first resources need to be reselected, wherein a priority of the first coordination information is equal to the highest priority of the first sidelink information and the second sidelink information.

[0243] For example, the processor 2110 may be configured to execute a program to implement the inter-device coordination method described in the embodiments of the second aspect. For example, the processor 2110 may be configured to perform the following control: receive first sidelink information from a second terminal device and second sidelink information from a third terminal device; determine based on the first sidelink information and the second sidelink information that the first sidelink information and the second sidelink information need to be retransmitted; and send second coordination information to the second terminal device indicating that the first sidelink information needs to be retransmitted and send third coordination information to the third terminal device indicating that the second sidelink information needs to be retransmitted, where a priority of the second coordination information is equal to a priority of the first sidelink information and a priority of the third coordination information is equal to a priority of the second sidelink information.

[0244] For example, the processor 2110 may be configured to execute a program to implement the inter-device coordination method described in the embodiment of the third aspect. For example, the processor 2110 may be configured to perform the following control: receive sidelink information from a second terminal device; and, depending on whether the second terminal device is a destination terminal device, send a reselection instruction to the second terminal device to instruct it to perform resource reselection and / or an acknowledgement (ACK) or non-acknowledgement (NACK) of the sidelink information.

[0245] For example, the processor 2110 may be configured to execute a program to implement the inter-device coordination method described in the embodiment of the third aspect. For example, the processor 2110 may be configured to perform the following control: transmit sidelink information; and receive a reselection instruction for instructing one or more first terminal devices to perform resource reselection and / or an acknowledgement (ACK) or non-acknowledgement (NACK) of the sidelink information.

[0246] For example, the processor 2110 may be configured to execute a program to implement the inter-device coordination method described in the embodiment of the fourth aspect. For example, the processor 2110 may be configured to perform the following control: receive sidelink information from a second terminal device; and send a reselection instruction to the second terminal device to instruct the second terminal device to perform resource reselection using a first resource or a second resource depending on whether the second terminal device is a destination terminal device.

[0247] For example, the processor 2110 may be configured to execute a program to implement the inter-device coordination method described in the embodiment of the fourth aspect. For example, the processor 2110 may be configured to perform the following control: transmit sidelink information; and receive an acknowledgement (ACK) or non-acknowledgement (NACK) of the sidelink information transmitted by one or more first terminal devices, and / or a reselection instruction for instructing the first terminal device to perform resource reselection, transmitting using the first resource and / or the second resource.

[0248] For example, the processor 2110 may be configured to execute a program to implement the inter-device coordination method described in the embodiment of the fifth aspect. For example, the processor 2110 may be configured to perform the following control: randomly or pseudo-randomly select and send M pieces of coordination information from N pieces of coordination information, where M is smaller than N and both are positive integers.

[0249] For example, the processor 2110 may be configured to implement a program to implement the inter-device coordination method described in the sixth aspect. For example, the processor 2110 may be configured to perform the following control: receive first sidelink information from a second terminal device and second sidelink information from a third terminal device; determine, based on the first sidelink information and the second sidelink information, that a first resource reserved by the first sidelink information needs to be reselected; and, if the first terminal device is an intended receiving terminal device of the second terminal device, or if the first terminal device is not an intended receiving terminal device of the second terminal device but is an intended receiving terminal device of the third terminal device, send first coordination information from the first terminal device to the second terminal device to indicate that the first resource needs to be reselected.

[0250] As shown in Fig. 21, the terminal device 2100 may further include a communication module 2130, an input unit 2140, a display 2150, a power supply 2160, etc. The functions of these components are the same as those of the prior art, so detailed descriptions thereof will be omitted here. Note that the terminal device 2100 does not need to include all of the components shown in Fig. 21. The terminal device 2100 may also include components not shown in Fig. 21, but reference can be made to the prior art for this information.

[0251] An embodiment of the present invention further provides a computer program, which, when executed by a terminal device, causes the terminal device to perform the inter-device coordination method described in the embodiments of the first to sixth aspects.

[0252] An embodiment of the present invention further provides a storage medium storing a computer program, wherein the computer program causes a terminal device to execute the inter-device coordination method described in the embodiments of the first to sixth aspects.

[0253] The above-described apparatus and methods may be realized by software or hardware, or by a combination of hardware and software. The present invention also relates to a computer-readable program as described below, which, when executed by a logic component, causes the logic component to realize the above-described apparatus or component, or to perform the above-described various methods or steps. The logic component may be, for example, an FPGA (Field Programmable Gate Array), a microprocessor, or a processing unit used in a computer. The present invention also relates to a storage medium, such as a hard disk, magnetic disk, optical hard disk, DVD, or flash memory, that stores the above-described program.

[0254] Furthermore, one or more combinations of the functional blocks illustrated in the figures and / or one or more combinations of the functional blocks may be implemented as a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic component, a discrete gate or transistor logic component, a discrete hardware assembly, or any other suitable combination for performing the functions described herein. Also, one or more combinations of the functional blocks illustrated in the figures and / or one or more combinations of the functional blocks may further be configured as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors communicatively coupled with a DSP, or any other configuration.

[0255] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and any modifications to the present invention fall within the scope of the present invention as long as they do not depart from the spirit of the present invention.

[0256] Furthermore, the following additional notes are disclosed regarding the above-described embodiments.

[0257] (Appendix 1) A method for coordination between devices, comprising: a first terminal device receiving first sidelink information from a second terminal device and second sidelink information from a third terminal device; the first terminal device determines, based on the first sidelink information and the second sidelink information, that the first resource reserved by the first sidelink information needs to be reselected; and the first terminal device transmitting first coordination information to the second terminal device to indicate that the first resource needs to be reselected; wherein a priority of the first coordination information is equal to a highest priority among the first sidelink information and the second sidelink information.

[0258] (Appendix 2) 2. The method of claim 1, comprising: the first sidelink information comprises first sidelink control information (SCI) and a first physical sidelink shared channel (PSSCH), the priority of the first sidelink information being equal to a priority indicated by a field in the first sidelink control information; the second sidelink information comprises second sidelink control information (SCI) and a second physical sidelink shared channel (PSSCH), and a priority of the second sidelink information is equal to a priority indicated by a field in the second sidelink control information.

[0259] (Appendix 3) 10. The method of claim 2, wherein the first resources reserved by the first sidelink control information and the second resources reserved by the second sidelink control information at least partially overlap in time and frequency domains.

[0260] (Appendix 4) 4. The method of any one of claims 1 to 3, comprising: The first coordination information is carried by a physical sidelink feedback channel (PSFCH).

[0261] (Appendix 5) 5. The method of any one of claims 1 to 4, comprising: the first terminal device is a target receiving terminal device of the second terminal device; Alternatively, the first terminal device is not an intended receiving terminal device of the second terminal device, but the first terminal device is an intended receiving terminal device of the third terminal device.

[0262] (Appendix 6) 6. The method of any one of claims 1 to 5, comprising: The second terminal device performs sidelink communication via unicast, groupcast, or broadcast.

[0263] (Appendix 7) The method of claim 1, further comprising: the first terminal device determines, based on the first sidelink information and the second sidelink information, that the first sidelink information and the second sidelink information need to be retransmitted; and the first terminal device transmitting second coordination information to the second terminal device, the second coordination information instructing that the first sidelink information needs to be retransmitted, and the third terminal device transmitting third coordination information instructing that the second sidelink information needs to be retransmitted; wherein a priority of the second coordination information is equal to a priority of the first sidelink information, and a priority of the third coordination information is equal to a priority of the second sidelink information.

[0264] (Appendix 8) 8. The method of claim 7, the first sidelink information comprises first sidelink control information (SCI) and a first physical sidelink shared channel (PSSCH), the priority of the first sidelink information being equal to a priority indicated by a field in the first sidelink control information; the second sidelink information comprises second sidelink control information (SCI) and a second physical sidelink shared channel (PSSCH), and a priority of the second sidelink information is equal to a priority indicated by a field in the second sidelink control information.

[0265] (Appendix 9) 8. The method of claim 7, wherein the resources in which the first sidelink information is located and the resources in which the second sidelink information is located at least partially overlap in time domain.

[0266] (Appendix 10) 10. The method of any one of appendices 7 to 9, comprising: The method, wherein the second terminal is an intended receiving terminal of the third terminal, and the third terminal is an intended receiving terminal of the second terminal.

[0267] (Appendix 11) 11. The method of any one of appendices 7 to 10, comprising: The second coordination information and the third coordination information are carried by a physical sidelink feedback channel (PSFCH).

[0268] (Appendix 12) 12. The method of any one of claims 7 to 11, further comprising: The first terminal device randomly or pseudo-randomly selects and transmits M pieces of coordination information from among N pieces of coordination information; wherein M is smaller than N and both are positive integers.

[0269] (Appendix 13) 13. The method of any one of claims 6 to 12, comprising: the second terminal device performs sidelink communication via unicast, groupcast, or broadcast; Alternatively, the second terminal device performs sidelink communication of a first groupcast, and one or more receiving terminal devices in the first groupcast feed back a negative acknowledgement (NACK) using the same physical sidelink feedback channel resource.

[0270] (Appendix 14) 14. The method of any one of claims 1 to 13, further comprising: A method including the first terminal device instructing the second terminal device that there is no need to perform resource reselection when the first terminal device determines that it will send an acknowledgement (ACK) to the second terminal device and there is no cancellation of the sending of the acknowledgement (ACK) due to a priority rule.

[0271] (Appendix 15) A method for coordination between devices, comprising: The first terminal device receives sidelink information from the second terminal device; and A method comprising: sending a reselection instruction to the second terminal device to instruct it to perform resource reselection and / or an acknowledgement (ACK) or non-acknowledgement (NACK) of the sidelink information depending on whether the first terminal device is a destination terminal device of the second terminal device.

[0272] (Appendix 16) 16. The method of claim 15, A method for transmitting the reselection instruction and the non-acknowledgement (NACK) to the second terminal device when the first terminal device is a target terminal device of the second terminal device and the second terminal device needs to perform row resource reselection.

[0273] (Appendix 17) 17. The method of claim 16, When executing a priority rule, the reselection instruction and the non-confirmation are treated as one feedback information, and a priority sorting is performed, and the priority of the feedback information is equal to the highest priority of the reselection instruction and the non-confirmation.

[0274] (Appendix 18) 16. The method of claim 15, A method for transmitting the reselection instruction to the second terminal device when the first terminal device is not a target terminal device of the second terminal device and the second terminal device needs to perform resource reselection.

[0275] (Appendix 19) 19. The method of any one of appendixes 13 to 18, comprising: The reselection indication is carried by a physical sidelink feedback channel (PSFCH).

[0276] (Appendix 20) 19. The method of claim 18, a slot of a physical sidelink feedback channel carrying the reselection indication is the same as a slot of a physical sidelink feedback channel carrying an acknowledgement (ACK) or a non-acknowledgement (NACK); The resource blocks (RBs) and / or sequence of the physical sidelink feedback channel carrying the reselection indication are configured or preconfigured and are different from the resource blocks (RBs) or sequence of the physical sidelink feedback channel carrying an acknowledgement (ACK) or a non-acknowledgement (NACK).

[0277] (Appendix 21) 19. The method of claim 18, The method, wherein the slot of the physical sidelink feedback channel carrying the reselection indication is different from the slot of the physical sidelink feedback channel carrying an acknowledgement (ACK) or a non-acknowledgement (NACK).

[0278] (Appendix 22) 22. The method of any one of claims 15 to 21, comprising: The second terminal device performs sidelink communication via unicast, groupcast, or broadcast: Alternatively, the second terminal device performs sidelink communication of a first groupcast, and in the first groupcast, a receiving terminal device feeds back a non-acknowledgement using the same physical sidelink feedback channel resource.

[0279] (Appendix 23) 23. The method of any one of claims 15 to 22, further comprising: A method including the first terminal device instructing the second terminal device that there is no need to perform resource reselection when the first terminal device determines that it will send an acknowledgement (ACK) to the second terminal device and there is no cancellation of the sending of the acknowledgement (ACK) due to a priority rule.

[0280] (Appendix 24) A method for coordination between devices, comprising: The second terminal device transmits sidelink information; and A method comprising receiving a reselection instruction for instructing one or more first terminal device transmissions to perform resource reselection and / or an acknowledgement (ACK) or non-acknowledgement (NACK) of the sidelink information.

[0281] (Appendix 25) 25. The method of claim 24, further comprising: The method includes performing resource reselection when the second terminal device determines that the transmission is a non-acknowledgement (NACK) or discontinuous transmission (DTX) and receives the reselection instruction.

[0282] (Appendix 26) 25. The method of claim 24, further comprising: The method includes the second terminal device determining, if it determines that the signal is an acknowledgment (ACK), that the sidelink information has already been received correctly.

[0283] (Appendix 27) 25. The method of claim 24, further comprising: determining that the sidelink information was not received correctly when the second terminal device determines that the sidelink information is not acknowledged (NACK) or discontinuous transmission (DTX) but does not receive the reselection indication.

[0284] (Appendix 28) 28. The method of any one of claims 24 to 27, comprising: the second terminal device performs sidelink communication via unicast, groupcast, or broadcast; Alternatively, the second terminal device performs sidelink communication of a first groupcast, and in the first groupcast, a receiving terminal device feeds back a non-acknowledgement using the same physical sidelink feedback channel resource.

[0285] (Appendix 29) A method for coordination between devices, comprising: The first terminal device receives sidelink information from the second terminal device; and The method includes transmitting a reselection instruction to the second terminal device to instruct the second terminal device to perform resource reselection using a first resource or a second resource depending on whether the first terminal device is a destination terminal device of the second terminal device.

[0286] (Appendix 30) 29. The method of claim 29, A method for transmitting the reselection instruction to the second terminal device using the first resource when the first terminal device is a target terminal device of the second terminal device and the second terminal device needs to perform row resource reselection.

[0287] (Appendix 31) 29. The method of claim 29, A method in which, when the first terminal device is a target terminal device of the second terminal device and the second terminal device needs to perform row resource reselection, the first terminal device sends the reselection instruction to the second terminal device using the first resource and skips sending a non-acknowledgement (NACK) to the second terminal device.

[0288] (Appendix 32) 32. The method of claim 30 or 31, The method, wherein the first resource is a physical sidelink feedback channel (PSFCH) resource.

[0289] (Appendix 33) 32. The method of claim 30 or 31, a slot of the first resource carrying the reselection indication is the same as a slot of a physical sidelink feedback channel carrying an acknowledgement (ACK) or a non-acknowledgement (NACK); The resource blocks (RBs) and / or sequence of the first resources carrying the reselection indication are configured or preconfigured and are different from the resource blocks (RBs) or sequence of the physical sidelink feedback channel carrying the acknowledgement (ACK) or non-acknowledgement (NACK).

[0290] (Appendix 34) 32. The method of claim 30 or 31, A method in which the slots of the first resource carrying the reselection indication are different from the slots of the physical sidelink feedback channel carrying an acknowledgement (ACK) or a non-acknowledgement (NACK).

[0291] (Appendix 35) 29. The method of claim 29, A method for transmitting the reselection instruction to the second terminal device using the second resource when the first terminal device is not the target terminal device of the second terminal device and the second terminal device needs to perform resource reselection.

[0292] (Appendix 36) 36. The method of claim 35, The method, wherein the second resource is different from the first resource.

[0293] (Appendix 37) 36. The method of claim 35, The method, wherein the second resource is a physical sidelink feedback channel (PSFCH) resource.

[0294] (Appendix 38) 38. The method of claim 37, a slot of the second resource carrying the reselection indication is the same as a slot of a physical sidelink feedback channel carrying an acknowledgement (ACK) or a non-acknowledgement (NACK); The resource blocks (RBs) and / or sequence of the second resources carrying the reselection indication are configured or preconfigured and are different from the resource blocks (RBs) or sequence of the physical sidelink feedback channel carrying the acknowledgement (ACK) or non-acknowledgement (NACK).

[0295] (Appendix 39) 38. The method of claim 37, A method in which the slots of the second resource carrying the reselection indication are different from the slots of the physical sidelink feedback channel carrying an acknowledgement (ACK) or a non-acknowledgement (NACK).

[0296] (Appendix 40) 40. The method of any one of claims 29 to 39, comprising: the first resource and the second resource are physical sidelink feedback channel (PSFCH) resources, and a slot of the first resource is the same as a slot of the second resource; A method, wherein resource blocks (RBs) and / or sequences of the first resource and the second resource are configured or pre-configured, and the first resource is different from the resource blocks (RBs) or sequence of the second resource.

[0297] (Appendix 41) 41. The method of any one of claims 29 to 40, comprising: the second terminal device performs sidelink communication via unicast, groupcast, or broadcast; Alternatively, the second terminal device performs sidelink communication of a first groupcast, and in the first groupcast, a receiving terminal device feeds back a non-acknowledgement using the same physical sidelink feedback channel resource.

[0298] (Appendix 42) 42. The method of any one of claims 29 to 41, further comprising: A method including the first terminal device instructing the second terminal device that there is no need to perform resource reselection when the first terminal device determines that it will send an acknowledgement (ACK) to the second terminal device and there is no cancellation of the sending of the acknowledgement (ACK) due to a priority rule.

[0299] (Appendix 43) A method for coordination between devices, comprising: The second terminal device transmits sidelink information; and A method comprising receiving an acknowledgement (ACK) or non-acknowledgement (NACK) of the sidelink information of one or more first terminal device transmissions, and / or a reselection instruction for instructing the first terminal device to perform resource reselection, the reselection instruction being transmitted using a first resource and / or a second resource.

[0300] (Appendix 44) 44. The method of claim 43, further comprising: determining, when the second terminal device determines that the sidelink information has been received correctly and does not receive a reselection instruction on the first resource, that the sidelink information has already been received correctly.

[0301] (Appendix 45) 44. The method of claim 43, further comprising: determining that the sidelink information was not received correctly when the second terminal device determines that the transmission is a non-acknowledgement (NACK) or discontinuous transmission (DTX) and does not receive a reselection instruction on the first resource and the second resource.

[0302] (Appendix 46) 44. The method of claim 43, further comprising: The method includes performing resource reselection when the second terminal device determines that the signal is a confirmation and receives a reselection instruction on the first resource, or when the second terminal device determines that the signal is a non-confirmation or DTX and receives a reselection instruction on the first resource or the second resource.

[0303] (Appendix 47) 47. The method of any one of claims 43 to 46, comprising: the second terminal device performs sidelink communication via unicast, groupcast, or broadcast; Alternatively, the second terminal device performs sidelink communication of a first groupcast, and in the first groupcast, a receiving terminal device feeds back a non-acknowledgement using the same physical sidelink feedback channel resource.

[0304] (Appendix 48) A method for coordination between devices, comprising: a first terminal device receiving first sidelink information from a second terminal device and second sidelink information from a third terminal device; the first terminal device determines, based on the first sidelink information and the second sidelink information, that the first sidelink information and the second sidelink information need to be retransmitted; and the first terminal device transmitting second coordination information to the second terminal device, the second coordination information instructing that the first sidelink information needs to be retransmitted, and the third terminal device transmitting third coordination information instructing that the second sidelink information needs to be retransmitted; wherein a priority of the second coordination information is equal to a priority of the first sidelink information, and a priority of the third coordination information is equal to a priority of the second sidelink information.

[0305] (Appendix 49) 49. The method of claim 48, the first sidelink information comprises first sidelink control information (SCI) and a first physical sidelink shared channel (PSSCH), the priority of the first sidelink information being equal to a priority indicated by a field in the first sidelink control information; the second sidelink information comprises second sidelink control information (SCI) and a second physical sidelink shared channel (PSSCH), and a priority of the second sidelink information is equal to a priority indicated by a field in the second sidelink control information.

[0306] (Appendix 50) 49. The method of claim 48, wherein the resources in which the first sidelink information is located and the resources in which the second sidelink information is located at least partially overlap in time domain.

[0307] (Appendix 51) 51. The method of any one of claims 48 to 50, comprising: The method, wherein the second terminal is an intended receiving terminal of the third terminal, and the third terminal is an intended receiving terminal of the second terminal.

[0308] (Appendix 52) 52. The method of any one of claims 48 to 51, comprising: The second coordination information and the third coordination information are carried by a physical sidelink feedback channel (PSFCH).

[0309] (Appendix 53) 53. The method of any one of claims 48 to 52, further comprising: The first terminal device randomly or pseudo-randomly selects and transmits M pieces of coordination information from among N pieces of coordination information; wherein M is smaller than N and both are positive integers.

[0310] (Appendix 54) 54. The method of any one of claims 48 to 53, comprising: the second terminal device performs sidelink communication via unicast, groupcast, or broadcast; Alternatively, the second terminal device performs sidelink communication of a first groupcast, and in the first groupcast, a receiving terminal device feeds back a non-acknowledgement using the same physical sidelink feedback channel resource.

[0311] (Appendix 55) 55. The method of any one of claims 48 to 54, further comprising: A method including the first terminal device instructing the second terminal device that there is no need to perform resource reselection when the first terminal device determines that it will send an acknowledgement (ACK) to the second terminal device and there is no cancellation of the sending of the acknowledgement (ACK) due to a priority rule.

[0312] (Appendix 56) A method for coordination between devices, comprising: a first terminal device receiving first sidelink information from a second terminal device and second sidelink information from a third terminal device; the first terminal device determines, based on the first sidelink information and the second sidelink information, that the first resource reserved by the first sidelink information needs to be reselected; and A method comprising: when the first terminal device is a target receiving terminal device of the second terminal device, or when the first terminal device is not a target receiving terminal device of the second terminal device but is a target receiving terminal device of the third terminal device, the first terminal device sending first coordination information to the second terminal device to indicate that the first resource needs to be reselected.

[0313] (Appendix 57) A method for coordination between devices, comprising: The first terminal device randomly or pseudo-randomly selects and transmits M pieces of coordination information from among the N pieces of coordination information; wherein M is smaller than N and both are positive integers.

[0314] (Appendix 58) A method for coordination between devices, comprising: determining that the first terminal device sends an acknowledgement (ACK) to the second terminal device; and The method includes the first terminal device instructing the second terminal device that there is no need to perform resource reselection if there is no cancellation of the transmission of the acknowledgment (ACK) due to a priority rule.

[0315] (Appendix 59) A terminal device, a memory and a processor; The storage device stores a computer program, A terminal device, wherein the processor is configured to execute the computer program to implement the inter-device coordination method described in any one of Supplementary Notes 1 to 58.

[0316] (Appendix 60) 60. A communication system comprising the terminal device of claim 59.

Claims

1. An inter-device coordination device, a receiver for receiving first sidelink information from a second terminal device and second sidelink information from a third terminal device; a processor for determining, based on the first sidelink information and the second sidelink information, that a collision occurs in a first resource reserved by the first sidelink information; and a transmitter for transmitting first coordination information to the second terminal device to indicate that a collision occurs in the first resource; a priority of the first coordination information is set equal to the highest priority of the first side link information and the second side link information; An inter-device coordination device, wherein the first coordination information is carried by a physical sidelink feedback channel.

2. 2. The inter-device coordination device according to claim 1, the first SLIC information comprises first SLIC control information and a first PSS channel, the priority of the first SLIC information being equal to a priority indicated by a field in the first SLIC information; the second sidelink information comprises second sidelink control information and a second physical sidelink shared channel, and a priority of the second sidelink information is equal to a priority indicated by a field in the second sidelink control information.

3. 3. The inter-device coordination device according to claim 2, An inter-device coordination device, wherein the first resource reserved by the first sidelink control information and the second resource reserved by the second sidelink control information at least partially overlap in the time domain and the frequency domain.

4. 2. The inter-device coordination device according to claim 1, An apparatus for inter-device coordination, wherein a first terminal device is a destination receiving terminal device of said second terminal device.

5. 2. The inter-device coordination device according to claim 1, An inter-device coordination apparatus, wherein a first terminal device is not a target receiving terminal device of the second terminal device, but the first terminal device is a target receiving terminal device of the third terminal device.

6. 2. The inter-device coordination device according to claim 1, The second terminal device is an inter-device coordination device that performs sidelink communication via unicast, groupcast, or broadcast.

7. 2. The inter-device coordination device according to claim 1, the processor is further adapted to determine, based on the first sidelink information and the second sidelink information, whether the first sidelink information and the second sidelink information need to be retransmitted; and the transmitter is further adapted to transmit, to the second terminal device, second coordination information for indicating that the first sidelink information needs to be retransmitted, and to transmit, to the third terminal device, third coordination information for indicating that the second sidelink information needs to be retransmitted; An inter-device coordination device, wherein a priority of the second coordination information is equal to a priority of the first side link information, and a priority of the third coordination information is equal to a priority of the second side link information.

8. 8. The inter-device coordination device according to claim 7, the first SLIC information comprises first SLIC control information and a first PSS channel, the priority of the first SLIC information being equal to a priority indicated by a field in the first SLIC information; the second sidelink information comprises second sidelink control information and a second physical sidelink shared channel, and a priority of the second sidelink information is equal to a priority indicated by a field in the second sidelink control information.

9. 9. The inter-device coordination device according to claim 8, The resource in which the first sidelink information is located and the resource in which the second sidelink information is located are at least partially overlapped in the time domain.

10. 8. The inter-device coordination device according to claim 7, The inter-device coordination device, wherein the second terminal device is a destination receiving terminal device of the third terminal device, and the third terminal device is a destination receiving terminal device of the second terminal device.

11. 8. The inter-device coordination device according to claim 7, The second coordination information and the third coordination information are carried by a physical sidelink feedback channel.

12. 8. The inter-device coordination device according to claim 7, the transmitter is further adapted to randomly or pseudo-randomly select and transmit M pieces of coordination information from among the N pieces of coordination information; An inter-device coordination device, wherein M is smaller than N, and both M and N are positive integers.

13. 1. A communication system comprising: a first terminal device; the first terminal device receives first sidelink information from a second terminal device and second sidelink information from a third terminal device; determines, based on the first sidelink information and the second sidelink information, that a collision occurs on a first resource reserved by the first sidelink information; and sends first coordination information to the second terminal device, indicating that a collision occurs on the first resource; a priority of the first coordination information is set equal to the highest priority of the first side link information and the second side link information; A communication system, wherein the first coordination information is carried by a physical sidelink feedback channel.

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